Mordant vehicle for color image transfer receivers

ABSTRACT

The use of a hydrophobic, alkali-permeable polymer as a binder for a dye mordant in a dye image-receiving layer employed in color diffusion transfer systems results in less stain than conventional gelatin vehicles.

United States Patent Abbott lMarch 20, 1973 MORDANT VEHICLE FOR COLOR [56] References Cited F EIVER IMAGE TRANS ER REC 8 UNITED STATES PATENTS [75] Inventor: Thomas 1. Abbott, Rochester, N.Y.

3,625,694 12/1971 Cohen et a]. ..96/84 [73] Assignee: Eastman Kodak Company,

Rochester, N.Y. Primary Examiner-J. Travis Brown Assistant Examiner-Alfonso T. Suro Pico [22] Flled 1971 Attorney-Robert W. Hampton et a1. [21] Appl. No.: 174,545

[57] ABSTRACT 52 US. Cl ..96/29 D, 96/3, 96/57, The use of a hydrophobic, alkali-Permeable Polymer 96/77 96/84 A as a binder for a dye mordant in a dye image-receiving layer employed in color diffusion transfer systems :2 "'gj j ffgg results in less stain than conventional gelatin vehicles.

23 Claims, No Drawings MORDANT VEHICLE FOR COLOR HVlAGE TRANSFER RECEIVERS This invention relates to the art of photography and more particularly to color diffusion transfer film units, reception elements and methods for obtaining stable, positive, right-reading diffusion transfer dye images of high quality. I

US. Pat. No. 3,227,550 of Whitmore and Mader issued Jan. 4, 1966 and US. Pat. No. 3,227,552 of Whitmore issued Jan. 4, 1966 describe photographic image transfer processes wherein an immobile coupler is reacted with oxidized color developer to form a mobile dye which is transferred by diffusion to a receiving layer to form a color image. During the development phase of the color development diffusion transfer process, the image dyes formed in the respective blue, green and red-sensitive silver halide emulsion layers diffuse into an image-receiving layer of the receiving element where the dyes are mordanted to form the transferred image. At the same time, small amounts of development reaction products and unused color developer diffuse into the image-receiving layer. When the receiving element is separated from the photosensitive element, oxygen in the atmosphere causes rapid oxidation of the unused developer; self-coupling of the developer occurs, thereby producing a yellowishbrown stain, particularly in the highlight or minimum density areas. It would be desirable to reduce the stain.

U.S. Pat. No. 3,445,228 issued May 20, 1969, of Beavers et al. discloses that a white pigment contained in an interlayer of a dye image-receiving element for use in the above-described process helps to conceal the stain formed in an acid layer and functions also as a timing layer. It would be desirable to provide an imagereceiving element wherein the staining propensities of the image-receiving layer are decreased.

US. Pat. Nos. 3,271,147; 3,271,148 and 3,312,549 describe various dye image-receiving layers for use in color diffusion transfer systems. The vehicles for dispersing the dye mordant are hydrophilic binders such as gelatin and various water-soluble cellulose derivatives.

It is an object of this invention to provide a film unit employing an image-receiving element capable of receiving stable dye images of high quality.

It is another object of this invention to provide a process for producing a transfer image wherein the receiving element does not require a post-processing washing step.

It is another object of this invention to provide an image-receiving element wherein the staining propensi ties of the dye image-receiving layer are decreased.

It is another object of this invention to provide a process of forming a transfer image employing a novel dye image-receiving element.

These and other objects are achieved by a photographic film unit according to my invention, which is adapted to be processed by passing the unit between a pair of juxtaposed pressure-applying members, such as would be found in a camera designed for in-camera processing, comprising:

a. a photosensitive element comprising a support having thereon at least one, and preferably three, photosensitive silver halide emulsion layers, each silver halide emulsion layer having associated therewith a dye image-providing material comprising a nondiffusible coupler capable of reacting with oxidized aromatic primary amino color developing agent to produce a diffusible dye;

. a dye image-receiving layer comprising a dye mordant dispersed in a hydrophobic, alkali-permeable binder; and

. a rupt'urable container containing an alkaline processing composition and which is adapted to be positioned during processing of the film unit so that a compressive force applied to the container by pressure-applying members in a camera will effect a discharge of the containers contents within the film unit;

the film unit containing an aromatic, primary amino color developing agent, preferably in the rupturable container.

The polymers used in accordance with my invention to disperse the dye mordant have a tendency to reduce the amount of unwanted development reaction products and unused color developer which normally accompany diffusible dye images formed by reacting an initially nondiffusible coupler with an oxidized, aromatic primary amino color developing agent. As mentioned above, unwanted development products and unused color developers on a dye imagereceiving layer are objectionable because of the tendency of these materials to form stain, particularly in the highlight or Dmin. areas.

Dye mordants normally employed in color diffusion transfer systems are usually dispersed in. hydrophilic colloids as described previously. Many of these dye image-receiving layers are designed for post-washing of the print to remove undesirable products. However, when left unwashed, the Dmin in such prints increases rapidly.

Use of a hydrophobic, alkali-permeable polymer as the binder for the dye mordant in accordance with my invention provides a relatively thin, hydrophobic element which can be produced from a non-aqueous medium. Since such mordant layers are much thinner than a gelatin mordant layer and because the element is water-impermeable yet alkali solution-permeable, unwanted development reaction products and unused color developer pick-up are held to a minimum without affecting dye imbibition. The elements also have improved physical properties such as repellency to the viscous processing composition, low curl, better gloss and improved dye stability.

Any polymer can be employed as the binder for the dye mordant in accordance with my invention as long as it is hydrophobic and alkali-permeable. Such polymers include ethyl cellulose which is especially preferred, polyvinyl acetal, or copolymers comprising recurring units of acrylic acid, acrylamide, sulfoalkyl acrylate, sulfoalkyl methacrylate, alkyl acrylate, alkyl methacrylate, etc. The remaining units of the copolymers can be derived from other ethylenically unsaturated monomers well known to those skilled in the art. Such copolymers are described, for example, in US. Pat. No. 3,411,911 of Dykstra issued Nov. 19, 1968; US. Pat. No. 3,411,912 of Dykstra et al. issued Nov. 19, 1968; US. Pat. No. 3,488,708 of Smith issued Jan. 6, 1970; and US. Pat. No. 3,220,844 of Houck et al. issued Nov. 30, 1965.

reaction 7 The amount of hydrophobic, alkali-permeable polymer to be used as the vehicle for the dye mordant can be varied widely depending upon the imaginga In one embodiment of my invention wherein the image-receiving element is separate from the photosensitive element, the novel dye image-receiving element comprises a support having thereon a dye imagereceiving layer comprising a dye mordant dispersed in a hydrophobic,alkali-permeable polymer.

A pH-lowering material layer and a timing layer, described hereinafter, can also be employed in the dye image-receiving element to increase the stability of the transferred image. Although not required, a lightreflective layer comprising a white pigment in a binder,

described hereinafter, can also be employed in the dye image-receiving element, if desired. The light-reflective layercan be located underneath the dye image-receiving layer or can be combined with a timing layer if one is employed.

The above-described dye image-receiving element of the film unit is adapted to be superposed on the photosensitive element after exposure thereof. The development and transfer operations can be effected by bathing either or both the exposed photosensitive element and the dye image-receiving element in a developing solution before rolling into contact with each other, or a viscous developing composition can be placed between the elements for spreading in a predetermined amount across and into contact with the exposed surface of the photosensitive elements. The viscous developing composition is desirably utilized in one or more pods attached to the reception sheet or photosensitive elementthat can be readily ruptured when development is desired as described, for example, in U.S. Pat. Nos. 2,559,643; 2,647,049; 2,661,293; 2,698,244; 2,698,798.; and 2,774,668.

During the development phase of a color diffusion transfer process according to my invention, thedye image-providing material formed in the respective blue-, greenand red-sensitive silver halide emulsion layers diffuse out of the photosensitive element through the'viscous developer composition and into the dye image-receiving layer, e.g., into the dye image receiving element described above, where the dyes are mordanted to form the transferred image.

In another embodiment of my invention, the dye image-receiving layer is located integral with the photosensitive element between the support and the lowermost photosensitive silver halide emulsion layer. Such integral receiver-negative photosensitive elements are described in copending U.S. application Ser.

No. 115,459 of Barr, Bushand Thomas filed Feb. 16, 1971 and now abandoned. In such an embodiment, the support for the-photosensitive element is transparent and is coated with the dye image-receiving layer, a substantially opaque, light-reflective layer, e.g., TiO,, and

the various layers forming the color-forming units. After exposure of the photosensitive element, a rupturable container containing an alkaline processing composition and an-opaque process sheet are brought into super-posed position. Pressure-applying membersin a camera rupture the container and spread.

processing composition over the photosensitive element as the film unit is withdrawn from the camera.

The processing compositiondevelops the exposed silver halide layers and dye images are formed as a function of development which diffuse to the image- 7 receiving layer to provide a positive, right-reading p image which is viewed through the transparent support on the opaque reflecting layer background. For further details concerning this particular integral film unit, its preparation and use, reference is made to the abovementioned U.S. application Ser. No. 115,459 of Barr,

' Bush and Thomas filed Feb. 16, 1971.

Another embodiment of integral receiver-negative photosensitive systems in which my invention can be employed is described in U.S. Ser. No. 1 15,552 of Cole filed Feb. 16, 1971 and now abandoned. In such an embodiment, the support for the color diffusion transfer system is transparent and is coated with the imagereceiving layer, a substantially opaque, light-reflective layer, e.g., TiO,, and then the various layers forming the color-forming units and a top transparent sheet. A rupturable container containing an alkaline processing composition and an opacifier is positioned adjacent to the top layer and sheet. The film unit is placed in camera, exposed through the top transparent sheet and then passed between a pair of pressure-applying members in the camera as it is being removed therefrom. The pressure-applying membersrupture the container and spread processing composition and opacifier over the negative portion of the film unit to render it lightinsensitive. The processing composition develops the exposed silver halide layers and dye images are formed as a result of development which diffuse to the imagereceiving layer to provide a positive, right-reading image which is viewed through the transparent support on the opaque reflecting layer background. For further details concerning this particular integral film unit, its preparation and use, reference is made to the abovementioned Cole U.S. application Ser. No. 115,552 filed idized aromatic primary'amino color developing agent in an alkaline processing composition. I

The nondiffusible couplers employed in this invention include those having the formulas:

DYE LINK (COUP BALL),

and

BALL LINK (COUP SOL),

wherein 1. DYE is a radical exhibiting selective absorption in the visible spectrum andcontaining an acidic solubilizing radical; I

. LINK is a connecting radical such as an azo radical, a mercuri radical, an oxy radical, an alkylidene radical, a thio radical, a dithio radical or an azoxy radical;

3. COUP is a coupler radical such as a S-pyrazolone coupler radical, a pyrazolotriazole coupler radical, a phenolic coupler radical or an open-chain ketomethylene coupler radical, COUP being substituted in the coupling position with LINK;

BALL is a photographically inert organic ballasting radical of such molecular size and configuration as to render such coupler nondiffusible during development in the alkaline processing composition;

5. SOL is a hydrogen atom or an acidic solubilizing group when the color developing agent contains an acidic solubilizing group, and SOL is an acidic solubilizing group when the color developing agent is free of an acidic solubilizing group; and

. n is an integer of l to 2 when LINK is an alkylidene radical, and n is 1 when LINK is an azo radical, a mercuri radical, an oxy radical, a thio radical, a dithio radical or an azoxy radical.

For further details concerning the above-described couplers, their preparation and use, reference is made to U.S. Pat. No. 3,227,550 of Whitmore et al. issued Jan. 4, I966; U.S. Pat. No. 3,227,552 of Whitmore issued Jan. 4, 1966; and British Pat. No. 904,364, page 19, lines 1-41.

The film assembly of my invention can be used to produce positive images in single or multicolors. In a three-color system, each silver halide emulsion layer of the film assembly of my invention will have associated therewith a dye image-providing material possessing a spectral absorption range substantially complementary to the predominant sensitivity range of its associated emulsion, i.e., the blue-sensitive silver halide emulsion layer will have a yellow dye image-providing material associated therewith, the green-sensitive silver halide emulsion layer will have a magenta dye image-providing material associated therewith, and the red-sensitive silver halide emulsion layer will have a cyan dye imageproviding material associated therewith. The dye image-providing material associated with each silver halide emulsion layer can be contained either in the silver halide emulsion layer itself or in a layer contiguous to the silver halide emulsion layer.

Spectral sensitizing dyes can be used conveniently to confer additional sensitivity to the light sensitive silver halide emulsion of the multilayer photographic elements of the invention. For instance, additional spectral sensitization can be obtained by treating the emulsion with a solution of a sensitizing dye in an organic solvent or the dye may be added in the form of a dispersion as described in Owens et al. British Pat. No. 1,154,781 issued June ll, 1969. For optimum results the dye can either be added to the emulsion as a final step or at some earlier stage.

sensitizing dyes useful in sensitizing such emulsions are described, for example, in Brooker et a]. U.S. Pat. No. 2,526,632, issued Oct. 24, 1950; Sprague U.S. Pat. No. 2,503,776, issued Apr. 11, 1950; Brooker et al. U.S. Pat. No. 2,493,748, issued Jan. 10, 1950; and Taber et al. U.S. Pat. No. 3,384,486 issued May 21, 1968. Spectral sensitizers which can be used include the cyanines, merocyanines, complex tri or tetranuclear) merocyanines, complex (tri or tetranuclear) cyanines, holopolar cyanines, 'styryls, hemicyanines (e.g. enamine hemicyanines), oxonols and hemioxonols. Dyes of the cyanine classes can contain such basic nuclei as the thiazolines, oxazolines,

pyrrolines, pyridines, oxazoles, thiazoles, selenazoles and imidazoles. Such nuclei can contain 'alkyl, alkylene, hydroxyalkyl, sulfoalkyl, carboxyalkyl, aminoalkyl and enamine groups and can be fused to carbocyclic or hetrocyclic ring systems either unsubstituted or substituted with halogen, phenyl, alkyl, haloalkyl, cyano, or alkoxy groups. The dyes can be symmetrical or unsymmetrical and can contain alkyl, phenyl, enamine or heterocyclic substituents on the methine or polymethine chain. The merocyanine dyes can contain the basic nuclei mentioned above as well as acid nuclei such as thiohydantoins, rhodanines, oxazolidenediones, thiazolidenediones, barbitur'ic acids, thiazolineones, and malononitrile. These acid nuclei can be substituted with alkyl, alkylene, phenyl, carboxyalkyl, sulfoalkyl, hydroxyalkyl, alkoxyalkyl, alkylamino groups, or heterocyclic nuclei. Combinations of these dyes can be used, if desired. In addition, supersensitizi'ng addenda which do not absorb visible light can be included, for instance, ascorbic acid derivatives, azaindenes, cadmium salts, and organic sulfonic acids as described in McFall et al. U.S. Pat. No. 2,933,390 issued Apr. 19, 1960 and Jones et al. U.S. Pat. No. 2,937,089 issued May 17, 1960.

The various silver halide emulsion layers of a color film assembly of the invention can be disposed in the usual order, i.e., the blue-sensitive silver halide emulsion layer first with respect to the exposure side, followed by the green-sensitive and red-sensitive silver halide emulsion layers. If desired, a yellow dye larger or a Carey Lea silver layer can be present between the bluesensitive and green-sensitive silver halide emulsion layer for absorbing or filtering blue blue radiation that may be transmitted through the blue-sensitive layer. If desired, the selectively sensitized silver halide emulsion layers can be disposed in a different order, e.g., the blue-sensitive layer first with respect to the exposure side, followed by the red-sensitive and green-sensitive layers.

The silver halide emulsions used in this invention can comprise, for example, silver chloride, silver bromide, silver chlorobromide, silver bromoiodide, silver chlorobromoiodide or mixtures thereof. The emulsions can be coarse or fine grain and can be prepared by any of the well-known procedures, e.g., single jet emulsions such as those described in Trivelli and Smith The Photographic Journal, Vol. LXXIX, May, 1939 (pp 330-338), double jet emulsions, such as Lippman emulsions, ammoniacal emulsions, thiocyanate or thioether ripened emulsions such as those described in Nietz et al. U.S. Pat. No. 2,222,264 issued Nov. 19, 1940; Illingsworth U.S. Pat. No. 3,320,069 issued May 16, 1967; and McBride U.S. Pat. No. 3,271,157 issued Sept. 6, 1966. Surface image emulsions can be used or internal image emulsions can be used such as those described in Davey at al U.S. Pat. No. 2,592,250 issued May 8, 1952; Porter et al. U.S. Pat. No. 3,206,313 issued Sept. 14, 1965; Berriman U.S. Pat. No. 3,367,778 issued Feb. 6, 1968; and Bacon et al. U.S. Pat. No.

Pat.

3,447,927 issued June 3,1969. The emulsions may be regular grain emulsions such as the type described in Klein and Moisar, J. Phat. Sci., Vol. 12, No. 5, Sept./Oct., 1964, (pp. 242-251). Negative type emulsions may be used or direct positive emulsions may be used such as those described in Leermakers U.S. Pat. No. 2,184,013 issued Dec. 19, 1939; Kendallet al. U.S. Patent No. 2,541,472 issued Feb. 13, 1951; Berriman U.S. Pat. No. 3,367,778 issued Feb. 6, 1968; Schouwenaars British Pat. No. 723,019 issued Feb. 2, 1955; lllingsworth et al. French Pat. No. 1,520,821 issued Mar. 4, 1968; lllingsworth U.S. Pat. No. 3,501,307 issued Mar. 17, 1970; Ives U.S. Pat. No. 2,563,785 issued Aug. 7, 1951; Knott et al. U.S. Pat. No. 2,456,953 issued Dec. 21, 1948; and Land U.S. Pat. No. 2,861,885 issued Nov. 25,1958.

The emulsions used with this invention may be sensitized with chemical sensitizers, such as with reducing agents; sulfur, selenium or tellurium compounds; gold, platinum of palladium compounds; or combinations of these. Suitable procedures are described in Sheppard et al. U.S. Pat. No. 1,623,499 issued Apr. 5, 1927; Waller et al. U.S. Pat. No. 2,399,083 issuedApr. 23, 1946; McVeigh U.S. Pat. No. 3,297,447 issued Jan. 10, 1967; and Dunn U.S. Pat. No. 3,297,446 issued Jan. 10,

The silver halide emulsions used with this invention may contain speed increasing compounds such as polyalkylene glycols, cationic surface active agents and thioethers or combinations of these as described in Piper U.S. Pat. No. 2,886,437 issued May 12, 1959; Dann et al. U.S. Pat. No. 3,046,134 issued July 24, 1962; Carroll et al. U.S. Pat. No. 2,944,900 issued July 12, 1960; and Goffe U.S. Pat. No. 3,294,540 issued Dec.27, 1966.

The silver halide emulsions used in the practice of this invention can be protected against the production of fog and can be stabilized against loss of sensitivity during keeping. Suitable'antifoggants and stabilizers each used alone or in combination include thiazolium salts described in Brooker et al. U.S. Pat. No. 2,131,038 issued Sept. 27, 1938; and Allen et al. U.S. Pat. No. 2,694,716 issued Nov. 16, 1954; the azaindenes described in Piper U.S. Pat. No. 2,886,437 issued May 12, 1959; and Heimbach et al. U.S. Pat. No. 2,444,605 issued July 6, 1948; the mercury salts as described in Allen et al. U.S. Pat. No. 2,728,663 issued Dec. 27, 1955; the urazoles described in Anderson et al. U.S. Pat. No. 3,287,135 issued Nov. 22, 1966; the sulfocatechols described in Kennard et al. U.S. Pat. No. 3,236,652 issued Feb. 22, 1966; the oximes described in Carroll et al. British Pat. No. 623,448 issued May 18, 1949; nitron; nitroindazoles; the mercaptotetrazoles described in Kendall et al. U.S. Pat. No. 2,403,927 issued July 16, 1946; Kennard et al. U.S. Pat. No. 3,266,897 issued Aug. 16, 1966; and Luckey et al. U.S. No. 3,397,987 issued Aug. 20, 1968; the polyvalent metal salts described in Jones U.S. Pat. No. 2,839,405 issued June 17, 1958; the thiuronium salts described in Herz et al. U.S. Pat. No. 3,220,839 issued Nov. 30, 1965; the palladium, platinum and gold salts described in Trivelli et al. U.S. Pat. No. 2,566,263 issued Aug. 28, 1951; and Yutzy et al. U.S. Pat. No. 2,597,915 issued May 27, 1952; and the tetrazoles described in Hoppe U.S. Pat. No. 3,352,672 issued Nov. 14,1967.

1f the silver halide emulsion employed with the nondiffusible couplers described above is a direct positive silver halide emulsion, such as an internal image emulsion or a solarizing emulsion, which is developable in unexposed areas, a positive image can be obtained on the dye image-receiving layer. In this embodiment,'the

' nondiffusible coupler can be located in the silver halide emulsion itself. After exposure of the film unit, the al- .kaline processing composition permeates the various layers to initiate development of the exposed photosen sitive silver halide emulsion layers. The aromatic primary amino color developing agent present in the film unit develops each of the silver halide emulsion layers in the unexposed areas (since the silver halide emulsions are direct positive ones), thus causing the developing agent to become oxidized imagewise corresponding to the unexposed areas of the direct positive silver halide emulsion layers. The oxidized developing agent then reacts with the nondiffusible coupler present in each silver halide emulsion layer to form imagewise distributions, respectively, of diffusible cyan, magenta and yellow dye as a function of the imagewise exposure of each of the silver halide emulsion layers. At least a portion of the imagewise distributions of diffusible cyan, magenta and yellow dye diffuse to the image-receiving layer to provide a positive dye image upon separation of the receiver from the negative.

Internal image silver-halide emulsions useful in the above-described embodiment are direct positive emulsions that form latent images predominantly inside the silver halide grains, as distinguished from silver halide grains that form latent images predominantly on the surface thereof. Such internal image emulsions were described by Davey et al. in U.S. Pat. No. 2,592,250 issued Apr. 8, 1952, and elsewhere in the literature. These emulsions can also contain fogging or nucleating agents such as those described in U.S. Pat. Nos. 2,588,982;2,563,785;3,227,552;etc.

As previously mentioned, the aromatic primary amino color developing agent employed in the abovedescribed embodiment is preferably present in the alkalineprocessing composition in the rupturable pod. The color developing agent can also be incorporated into the negative portion of the film unit as a separate layer, e.g., by employing a Schiff base derivative of an aromatic primary amino color developing agent such as that formed by reacting o-sulfobenzaldehyde and N,N- diethyl-3-methyl-4-aminoaniline. Such incorporated developing agent will be activated by the alkaline processing composition. While the incorporated developing agent canbe positioned in any layer of the silver halide emulsion layer containing a dye imageproviding material or having the dye image-providing material present in a contiguous layer may be separated from the other silver halide emulsion layers in the negative portion of the film unit by materials in addition to those described above, including gelatin, calcium alginate, or any of those disclosed in U.S. Pat. No. 3,384,483, polymeric materials such as polyvinylamides ad disclosed in U.S. Pat. No. 3,421,892, or any of those disclosed in U.S. Pat. Nos. 2,992,104; 3,043,692; 3,044,873; 3,121,011 and 3,427,158.

4-amino-N-ethyl-3-methyl-N -(B-sulfoethyl)aniline, 4-amino-N-ethyl-3-methoxy-N-(B-sulfoethyl)aniline, 4-amino-N-etl1yl-N-( B-hydroxyethyhaniline, 4-amino-N,N-diethyl-3-hydroxymethyl aniline, 4-amino-N-methyl-N-(B-carboxyethyDaniline, 5 4-amino-N,N-bis(B-hydroxyethyl)aniline, 4-amino-N,N-bis(B-hydroxyethyl)-3-methyl aniline, 3-acetamido-4-amino-N,N,-bis(B-hydroxyethyl)aniline, 4-amino-N-ethyl-N-(2,3,dihydroxypropyl)-3-methyl 0 aniline, 4-amino-N,N-diethyl-3-(3-hydroxypropoxy)ani1ine,

and the like.

In a color film unit according to the invention, eac

Generally speaking, except where noted otherwise,

the silver halide emulsion layers in the invention comprise photosensitive silver halide dispersed in gelatin and are about 0.6 to 6 microns in thickness; the dye image-providing materials are dispersed in an aqueous alkaline solution-permeable polymeric binder, such as gelatin, as a separate layer about 1 to 7 microns in thickness, polymeric interlayers, e.g., gelatin, are about 1 to 5 microns in thickness. Of course these thicknesses are approximate only and can be modified according to the product desired. In addition to gelatin, other suitable hydrophilic materials which can be employed include both naturally-occurring substances such as proteins,

e.g., polysaccharides such as dextran, gum arabic and the like; and synthetic polymeric substances such as water soluble polyvinyl rolidone), acrylamide polymers and the like.

and the alkaline solution-permeable gelatin derivatives, cellulose derivatives,

compounds like poly(vinylpyr- The photographic emulsion layers and other layers of a photographic element employed in the practice of this invention can also contain alone or in combination with hydrophilic, water-permeable colloids, other synthetic polymeric compounds such as dispersed vinyl compounds such as in latex form and particularly those which increase the dimensional stability of the photographic materials. Suitable synthetic polymers include those described for example, in Nottorf U.S. Pat. No. 3,142,568 issued July 28, 1964; White U.S. Pat. No. 3,193,386 issued July 6, 1965; Houck et a]. U.S. Pat. No. 3,062,674 issued Nov. 6, 1962; Houck et al. U.S. Pat. No. 3,220,844 issued Nov. 30, 1965; Ream et al. U.S. Pat. No. 3,287,289 issued Nov. 22, 1966; and Dykstra U.S. Pat. No. 3,41 1,911 issued Nov. 19, 1968. Particularly effective are those water-soluble polymers of alkyl acrylates and methacrylates, acrylic acid, sulfoalkyl acrylates or methacrylates, those which have cross-linking sites which facilitate hardening or curing described in Smith U.S. Pat. No. 3,488,708 issued Jan. 6, 1970, and those having recurring sulfobetaine units as described in Dykstra Canadian Pat. No. 774,054.

Any material can be employed as the dye mordant in this invention as long as the desired function of mordanting or otherwise fixing the dye images will be obtained. The particular material chosen will, of course, depend upon the dye to be mordanted. If acid dyes are to be mordanted, the image-receiving layer can contain basic polymeric mordants such as polymers of amino guanidine derivatives of vinyl methyl ketone such as described in Minsk U.S. Pat. No. 2,882,156 issued Apr. 14, 1959, and basic polymeric mordants such as described in copending U.S. Application Ser. No. 100,491 of Cohen et al. filed Dec. 21, 1970. Other mordants useful in my invention include poly-4-vinylpyridine, the 2-vinyl pyridine polymer metho-p-toluene sulfonate and similar compounds described in Sprague et a1. U.S. Pat. No. 2,484,430 issued Oct. 11, 1949, and cetyl trimethylammonium bromide, etc. Effective dye mordants are also described in Whitmore U.S. Pat. No. 3,271,148 and Bush U.S. Pat. No. 3,271,147, both issued Sept. 6, 1966.

The image-receiving layer can also contain ultraviolet absorbing materials to protect the mordanted dye images from fading due to ultraviolet light, brightening agents such as the stilbenes, coumarins, triazines, oxazoles, dye stabilizers such as the chromanols, alkylphenols, etc.

Use of a pH-lowering material associated with the dye image-receiving element of the invention will usually increase the stability of the transferred image. Generally, the pH-lowering material will effect a reduction in the pH of the image layer from about 13 or 14 to at least 11 andpreferably 5-8 within a short time after imbibition. For example, polymeric acids as disclosed in U.S. Pat. No. 3,362,819 or solid acids or metallic salts, e.g., zinc acetate, zinc sulfate, magnesium acetate, etc., as disclosed in U.S. Pat. No. 2,584,030 may be employed with good results. Such pH-lowering materials reduce the pH of the film unit after development to terminate development and substantially reduce further dye transfer and thus stabilize the dye image. The pH-lowering material can be present as a separate layer between the dye image-receiving layer and its support where the receiver is a separate element or between the dye image-receiving layer and the lowermost silver halide emulsion layer in an integral receiver-negative element.

An inert timing or spacer layer can be employed in the practice of my invention over the pH-lowering layer which times or controls the pH reduction as a function of the rate at which alkali diffuses through the inert spacer layer. Examples of such timing layers include gelatin, polyvinyl alcohol or any of those disclosed in U.S. Pat. No. 3,455,686. The timing layer is also effective in evening out the various reaction rates over a wide range of temperatures,e.g., premature pH reduction is prevented when inbibition is effected at temperatures above room temperature, for example, at to F. The timing layer is usually about 0.1 to about 0.7 mil in thickness and may contain a light reflective material, such as titanium dioxide, if desired. Especially good results are obtained when the timing layer comprises a hydrolyzable polymer or a mixture of such polymers which are slowly hydrolyzed by the processing composition. Examples of such hydrolyzable polymers include polyvinyl acetate, polyamides, cellulose esters, etc.

The alkaline processing composition employed in this invention is the conventional aqueous solution of an alkaline material, e.g., sodium hydroxide, sodium carbonate or an amine such as diethylamine, preferably possessing a pH in excess of 12, and preferably containing a developing agent as described previously. The solution also preferably contains a viscosity-increasing compound such as a high-molecular-weight polymer, e.g., a water-soluble ether inert to alkaline solutions such as hydroxyethyl cellulose or alkali metal salts of carboxymethyl cellulose such as sodium carboxymethyl cellulose. A concentration of viscosity-increasing compound of about 1 to about 5 percent by weight of the processing composition is preferred which will impart thereto a viscosity of about 100 cps. to about 200,000 cps.

While the alkaline processing composition used in this invention can be employed in a rupturable container, as described previously, other methods of applying processing composition could be employed, e.g., bathing the photosensitive element in a processing bath, interjecting processing composition with communicating members similar to hypodermic syringes which are attached either to a camera or camera cartridge, etc.

While the film units of my invention can be modified so as to be employed in roll form, they are preferably used in cartridges similar to those described in U.S. Pat. Nos. 3,080,805; 3,161,1 l8; and 3,161,122; said patents also illustrating typical cameras for performing color diffusion transfer processes of my invention.

The supports for the photographic elements of this invention can be any material as long as it does not deleteriously effect the photographic properties of the film unit and is dimensionally stable. Typical flexible sheet materials include cellulose nitrate film, cellulose acetate film, poly(vinyl acetal) film, polystyrene film poly(ethylene-terephthalate) film, polycarbonate film, poly-a-olefins such as polyethylene and polypropylene film, and related films or resinous materials as well as glass, paper, metal, etc. The support is usually about 2 to 6 mils in thickness.

While the invention has been described with reference to layers of silver halide emulsions and dye image-providing materials, dotwise coating, such as would be obtained using a gravure printing technique, could also be employed. In this technique, small dots of blue, green and red-sensitive emulsions have associated therewith, respectively, dots of yellow, magenta and cyan color-providing substances. After development, the transferred dyes would tend to fuse together into a continuous tone.

The photographic layers employed in the practice of this invention may contain surfactants such as saponin; anionic compounds such as the alkyl aryl sulfonates described in Baldsiefen U.S. Pat. No. 2,600,831 issued June 17, 1952; amphoteric compounds such as those described in Ben-Ezra U.S. Pat. No. 3,133,816 issued May 19, 1964; and water soluble adducts of glycidol and an alkyl phenol such as those described in Olin Mathieson British Pat. No. 1,022,878 issued March 16, 1966; and Knox U.S. Pat. No. 3,514,293 issued May 26, 1970.

The various layers, including the photographic layers, employed in the practice of this invention can Hughes U.S. Pat. No. 3,508,947 issued Apr. 28, 1970;

contain light absorbing materials and filter dyes such as '8 those described in Sawdey U.S. Pat. No. 3,253,921 issued May 31, 1966; Gaspar U.S. Pat. No. 2,274,782 issued Mar. 3, 1942; Silberstein et a1. U.S. Pat. No. 2,527,583 issued Oct. 31, 1950; and VanCampen U.S. Pat. No. 2,956,879 issued Oct. 18, 1960.

The sensitizing dyes and other addenda used in the practice of this invention can be added from water or extrusion coating using hoppers of the type described in Beguin U.S. Pat. No. 2,681,294 issued June 15, 1954. If desired, two or more layers may be coated simultaneously by the procedure described in Russell'U.S. Pat. No. 2,761,791 issued Sept. 4, 1956;

and Wynn British Pat. No. 837,095 issued June 9, 1960. This invention also can be used for silver halide layers coated by vacuum evaporation as described in British Pat. No. 968,453 issued Sept. 2, 1964 and Lu- Valle et a1. U.S. Pat. No. 3,219,451 issued Nov. 23, 1965.

The photographic and other hardenable layers used in the practice of this invention can be hardened by various organic or inorganic hardeners, alone or in combination, such as the aldehydes, and blocked a1- dehydes as described in Allen et al. U.S. Pat. No.

. 3,232,764 issued Feb. 1, 1966; ketones, carboxylic and carbonic acid derivatives, sulfonate esters, sulfonyl'halides and vinyl sulfonyl ethers as described in Burness et a1. U.S. Pat. No. 3,539,644 issued Nov. 10, 1970; active halogen compounds, epoxy compounds, aziridines, active olefins, isocyanates, carbodi-imides, polymeric hardeners such as oxidized polysaccharideslike dialdehyde starch and oxyguargum and the like.

The following example further illustrates the invention.

EXAMPLE Dye image-receiving elements are prepared by coat- The compositions are coated such that the dried coating from Composition A contains 250 milligrams gelatin and milligrams mordant and the dried coating from Composition B contains about milligrams ethyl cellulose and 160 milligrams mordant per square foot of support.

A multicolor photographic element of the type described in Example I of Whitmore et al. U.S. Pat. No. 3,227,550 issued Jan. 9, 1966, is prepared. The emulsions are direct positive, gelatino, silver bromoiodide emulsions containing cyan, magenta and yellow dye-forming couplers in the red, green and blue light-recording emulsions, respectively.

Samples of the above photosensitive element are exposed to a multicolor test object. The following processing composition is spread from a pod between the exposed surface of the elements and the superposed image-receiving elements by passing the transfer sandwich between a pair of juxtaposed pressure rollers:

benzyl alcohol 10.0 ml. sodium hydroxide 25.0 g. 4-amino-N-ethyl-N-fi-hydroxyethyl aniline 20.0 g. Smitrobenzimidazole 0.24 g. hydroxyethyl cellulose 30.0 g. Water to 1 liter After 60 seconds at about 24C, the dye imagereceiving elements are peeled apart from the negative. After several weeks keeping under room light conditions, the minimum densities are obtained as follows:

Mordant Composition D min Red Green Blue A (control) 1.04 1.32 1.81 B 0.50 0.52 0.95

The above results indicate the significant improvement in D min, which is attributable to less stain, which is obtained in the use of the dye image-receiving element according to my invention.

The invention has been described with particular reference to certain preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention.

lclaim:

1. In a photographic film unit which is adapted to be processed by passing said unit between a pair of juxtaposed pressure-applying members comprising:

a. a photosensitive element comprising a support having thereon at least one photosensitive silver halide emulsion layer, each said silver halide emulsion layer having associated therewith a non-diffusible coupler capable of reacting with oxidized aromatic primary amino color developing agent to produce a diffusible dye;

. a dye image-receiving layer comprising a dye mordant dispersed in a binder; and

c. a rupturable container containing an alkaline processing composition and which is adapted to be positioned during processing of said film unit so that a compressive force applied to said container by said pressure-applying members will effect a discharge of the containers contents within said film unit; said film unit containing an aromatic primary amino color developing agent; the improvement comprising employing a hydrophobic, alkali-permeable polymer as said binder.

2. The photographic film unit of claim 1 wherein said photosensitive element comprises a support having thereon a red-sensitive silver halide emulsion layer having associated therewith a cyan dye image-providing material comprising a non-diffusible coupler capable of reactingwith oxidized aromatic primary amino color developing agent to produce a diffusible cyan dye, a green-sensitive silver halide emulsion layer having associated therewith a magenta dye image-providing material comprising a nondiffusible coupler capable of reacting with oxidized aromatic primary amino color developing agent to produce a diffusible magenta dye, and ablue-sensitive silver halide emulsion layer having associated therewith a yellow dye image-providing material comprising a nondiffusible coupler capable of reacting with oxidized aromatic primary amino color developing agent to produce a diffusible yellow dye.

3. The film unit of claim 1 wherein said dye imagereceiving layer is located in said photosensitive element between said support and the lowermost photosensitive silver halide emulsion layer.

4. The film unit of claim 1 wherein said dye imagereceiving layer is coated on a separate support and is adapted to be superposed on said photosensitive element after exposure thereof.

5. The film unit of claim 4 wherein said rupturable container is so positioned during processing of said film unit that a compressive force applied to said container by said pressure-applying members will effect a discharge of the containers contents between said dye image-receiving layer and the outermost layer of said photosensitive element.

6. The film unit of claim 1 which also contains a pH- lowering material.

7. The film unit of claim 1 wherein said hydrophobic, alkali-permeable polymer is ethyl cellulose, polyvinyl acetal, or a copolymer comprising units of acrylic acid,

acrylamide, sulfoalkyl acrylate, sulfoalkyl methacry-' late, alkyl acrylate or alkyl methacrylate.

8. The film unit of claim 1 wherein said polymer is ethyl cellulose.

9. In a photographic film unit which is adapted to be processed by passing said unit between a pair of juxtaposed pressure-applying members comprising:

1. a photosensitive element comprising a support having thereon the following layers in sequence:

a. a direct-positive, red-sensitive silver halide emulsion layer containing a nondiffusible coupler capable of reacting with oxidized aromatic primary amino color developing agent to produce a diffusible cyan dye;

b. an alkaline solution-permeable interlayer containing a compound capable of scavenging oxidized aromatic primary amino color developing agent;

c. a direct-positive, greensensitive silver halide emulsion layer containing a nondiffusible coupler capable of reacting with oxidized aromatic primary amino color developing agent to produce a diffusible magenta dye;

d. an alkaline solution-permeable interlayer containing a compound capable of scavenging oxidized aromatic primary amino color developing agent; and

e. a direct-positive, blue-sensitive silver halide emulsion layer containing a nondiffusible coupler capable of reacting with oxidized aromatic primary amino color developing agent to produce a diffusible yellow dye; each said nondiffusible coupler having the formula:

DYE LINK (COUP BALL), or

BALL LINK (COUP SOL),

13. The reception element of claim 12 wherein said 'polymer is ethyl cellulose, polyvinyl acetal, or a copolymer comprising units of acrylic acid, acrylamide, sulfoalkyl acrylate, sulfoalkyl methacrylate, alkyl acrylate or alkyl methacrylate.

14. The reception element of claim 12 wherein said polymer is ethyl cellulose. v I

15. The reception element of claim 12 which includes a pH-lowering layer between said support and said dye image-receiving layer.

16. The reception element of claim 15 wherein said pI-I-lowering layer comprises a polymeric acid.

17. The reception element of claim 16 wherein a timing layer is present between said polymeric acid layer 4. BALL is a photographically inert organic ballasting radical of such molecular size and configuration as to render said coupler nondiffusible during development in said alkaline processing composition;

5. SOL is selected from the group consisting of a hydrogen atom and an acidic solubilizing group when said color developing agent contains an acidic solubilizing group, and SOL is an acidic solubilizing group when said color developing agent is free of an acidic solubilizing group; and

6. n is an integer of 1 to 2 when said LINK is an alkylidene radical, and n is 1 when said LINK is a radical selected from the group consisting of an azo radical, a mercuri radical, an oxy radical, a thio radical, a dithio radical and an azoxy radical;

II. a dye image-receiving element comprising a support having thereon a dye mordant dispersed in a binder, said element being adapted to be superposed over said blue-sensitive silver halide emulsion layer after exposure of said photosensitive element; and

III. a rupturable container containing an alkaline processing composition and which is adapted to be positioned during processing of said film unit so that a compressive force applied to saidv container by said pressure-applying members will effect a discharge of the containers contents between said dye image-receiving layer and said blue-sensitive silver halide emulsion layer of said photosensitive element;

said film unit containing an aromatic primary amino color developing agent; the improvement comprising employing a hydrophobic, alkali-permeable polymer as said binder.

l0. Thetilm unit of claim 9 wherein said hydrophobic, alkali-permeable polymer is ethyl cellulose, polyvinyl acetal, or a copolymer comprising units of acrylic acid, acrylamide, sulfoalkyl acrylate, sulfoalkyl methacrylate, alkyl acrylate or alkyl methacrylate.

11. The film unit of claim 9 wherein said polymer is ethyl cellulose.

12. A reception element comprising a support having thereon a dye image-receiving layer comprising a dye mordant dispersed in a hydrophobic, alkali-permeable polymer.

and said dye image-receiving layer.

18. The reception element of claim 17 wherein said hydrophobic, alkali-permeable polymer is ethyl cellulose, polyvinyl acetal, or a copolymer comprising units of acrylic acid, acrylamide, sulfoalkyl acrylate, sulfoalkyl methacrylate, alkyl acrylate or alkyl methacrylate.

19. The reception element of claim 17 wherein said hydrophobic, alkali-permeable polymer is ethyl cellulose.

20. In a process of forming a transfer image comprismg:

a. imagewise-exposing a photosensitive element comprising a support having thereon atleast one photosensitive silver halide emulsion layer, each tion of diffusible dye image-providing material dif-' fusing to a dye image-receiving layer comprising a dye mordant dispersed in a binder; the improvement comprising employing as said binder a hydrophobic, alkali-permeable polymer.

21. The process of claim 20 wherein said treatment step (b) is effected by A. superposing over the layer outermost from the support of said photosensitive element said dye image-receiving layer coated on a support;

B. positioning a rupturable container containing said alkaline processing composition between said exposed photosensitive element and said dye imagereceiving layer; and

C. applying a compressive force to said container to effect a discharge of the container's contents between said outermost layer of said exposed photosensitive element and said dye image-receiving layer.

22. The process of claim 21 wherein said polymer is ethyl cellulose, polyvinyl acetal, or a copolymer comprising units of acrylic acid, acrylamide, sulfoalkyl acrylate, sulfoalkyl methacrylate, alkyl acrylate or alkyl methacrylate.

ethyl cellulose. 

2. The photographic film unit of claim 1 wherein said photosensitive element comprises a support having thereon a red-sensitive silver halide emulsion layer having associated therewith a cyan dye image-providing material comprising a non-diffusible coupler capable of reacting with oxidized aromatic primary amino color developing agent to produce a diffusible cyan dye, a green-sensitive silver halide emulsion layer having associated therewith a magenta dye image-providing material comprising a nondiffusible coupler capable of reacting with oxidized aromatic primary amino color developing agent to produce a diffusible magenta dye, and a blue-sensitive silver halide emulsion layer having associated therewith a yellow dye image-providing material comprising a nondiffusible coupler capable of reacting with oxidized aromatic primary amino color developing agent to produce a diffusible yellow dye.
 2. LINK is a connecting radical selected from the group consisting of an azo radical, a mercuri radical, an oxy radical, an alkylidene radical, a thio radical, a dithio radical and an azoxy radical;
 3. COUP is a coupler radical selected from the group consisting of a 5-pyrazolone coupler radical, a pyrazolotriazole coupler radical, a phenolic coupler radical and an open-chain ketomethylene coupler radical, said COUP being substituted in the coupling position with said LINK;
 3. The film unit of claim 1 wherein said dye image-receiving layer is located in said photosensitive element between said support and the lowermost photosensitive silver halide emulsion layer.
 4. The film unit of claim 1 wherein said dye image-receiving layer is coated on a separate support and is adapted to be superposed on said photosensitive element after exposure thereof.
 4. BALL is a photographically inert organic ballasting radical of such molecular size and configuration as to render said coupler nondiffusible during development in said alkaline processing composition;
 5. SOL is selected from the group consisting of a hydrogen atom and an acidic solubilizing group when said color developing agent contains an acidic solubilizing group, and SOL is an acidic solubilizing group when said color developing agent is free of an acidic solubilizing group; and
 5. The film unit of claim 4 wherein said rupturable container is so positioned during processing of said film unit that a compressive force applied to said container by said pressure-applying members will effect a discharge of the container''s contents between said dye image-receiving layer and the outermost layer of said photosensitive element.
 6. The film unit of claim 1 which also contains a pH-lowering material.
 6. n is an integer of 1 to 2 when said LINK is an alkylidene radical, and n is 1 when said LINK is a radical selected from the group consisting of an azo radical, a mercuri radical, an oxy radical, a thio radical, a dithio radical and an azoxy radical; II. a dye image-receiving element comprising a support having thereon a dye mordant dispersed in a binder, said element being adapted to be superposed over said blue-sensitive silver halide emulsion layer after exposure of said photosensitive element; and III. a rupturable container containing an alkaline processing composition and which is adapted to be positioned during processing of said film unit so that a compressive force applied to said container by said pressure-applying members will effect a discharge of the container''s contents between said dye image-receiving layer and said blue-sensitive silver halide emulsion layer of said photosensitive element; said film unit containing an aromatic primary amino color developing agent; the improvement comprising employing a hydrophobic, alkali-permeable polymer as said binder.
 7. The film unit of claim 1 wherein said hydrophobic, alkali-permeable polymer is ethyl cellulose, polyvinyl acetal, or a copolymer comprising units of acrylic acid, acrylamide, sulfoalkyl acrylate, sulfoalkyl methacrylate, alkyl acrylate or alkyl methacrylate.
 8. The film unit of claim 1 wherein said polymer is ethyl cellulose.
 9. In a photographic film unit which is adapted to be processed by passing said unit between a pair of juxtaposed pressure-applying members comprising: I. a photosensitive element comprising a support having thereon the following layers in sequence: a. a direct-positive, red-sensitive silver halide emulsion layer containing a nondiffusible coupler capable of reacting with oxidized aromatic primary amino color developing agent to produce a diffusible cyan dye; b. an alkaline solution-permeable interlayer containing a compound capable of scavenging oxidized aromatic primary amino color developing agent; c. a direct-positive, green-sensitive silver halide emulsion layer containing a nondiffusible coupler capable of reacting with oxidized aromatic primary amino color developing agent to produce a diffusible magenta dye; d. an alkaline solution-permeable interlayer containing a compound capable of scavenging oxidized aromatic primary amino color developing agent; and e. a direct-positive, blue-sensitive silver halide emulsion layer containing a nondiffusible coupler capable of reacting with oxidized aromatic primary amino color developing agent to produce a diffusible yellow dye; each said nondiffusible coupler having the formula: DYE - LINK - (COUP - BALL)n or BALL - LINK - (COUP - SOL)n wherein:
 10. The film unit of claim 9 wherein said hydrophobic, alkali-permeable polymer is ethyl cellulose, polyvinyl acetal, or a copolymer comprising units of acrylic acid, acrylamide, sulfoalkyl acrylate, sulfoalkyl methacrylate, alkyl acrylate or alkyl methacrylate.
 11. The film unit of claim 9 wherein said polymer is ethyl cellulose.
 12. A reception element comprising a support having thereon a dye image-receiving layer comprising a dye mordant dispersed in a hydrophobic, alkali-permeable polymer.
 13. The reception element of claim 12 wherein said polymer is ethyl cellulose, polyvinyl acetal, or a copolymer comprising units of acrylic acid, acrylamide, sulfoalkyl acrylate, sulfoalkyl methacrylate, alkyl acrylate or alkyl methacrylate.
 14. The reception element of claim 12 wherein said polymer is ethyl cellulose.
 15. The reception element of claim 12 which includes a pH-lowering layer between said support and said dye image-receiving layer.
 16. The reception element of claim 15 wherein said pH-lowering layer comprises a polymeric acid.
 17. The reception element of claim 16 wherein a timing layer is present between said polymeric acid layer and said dye image-receiving layer.
 18. The reception element of claim 17 wherein said hydrophobic, alkali-permeable polymer is ethyl cellulose, polyvinyl acetal, or a copolymer comprising units of acrylic acid, acrylamide, sulfoalkyl acrylate, sulfoalkyl methacrylate, alkyl acrylate or alkyl methacrylate.
 19. The reception element of claim 17 wherein said hydrophobic, alkali-permeable polymer is ethyl cellulose.
 20. In a process of forming a transfer image comprising: a. imagewise-exposing a photosensitive element comprising a support having thereon at least one photosensitive silver halide emulsion layer, each said silver halide emulsion layer having associated therewith a nondiffusible coupler capable of reacting with oxidized aromatic primary amino color developing agent to produce a diffusible dye; b. treating the layer outermost from the support of said exposed photosensitive element with an alkaline processing composition to effect development of each of said exposed silver halide emulsion layers; c. forming an imagewise distribution of diffusible dye image-providing material as a function of said imagewise exposure of each said silver halide layer; and d. at least a portion of each said imagewise distribution of diffusible dye image-providing material diffusing to a dye image-receiving layer comprising a dye mordant dispersed in a binder; the improvement comprising employing as said binder a hydrophobic, alkali-permeable polymer.
 21. The process of claim 20 wherein said treatment step (b) is effected by A. superposing over the layer outermost from the support of said photosensitive element said dye image-receiving layer coated on a support; B. positioning a rupturable container containing said alkaline processing composition between said exposed photosensitive element and said dye image-receiving layer; and C. applying a compressive force to said container to effect a discharge of the container''s contents between said outermost layer of said exposed photosensitive element and said dye image-receiving layer.
 22. The process of claim 21 wherein said polymer is ethyl cellulose, polyvinyl acetal, or a copolymer comprising units of acrylic acid, acrylamide, sulfoalkyl acrylate, sulfoalkyl methacrylate, alkyl acrylate or alkyl methacrylate.
 23. The process of claim 21 wherein said polymer is ethyl cellulose. 